Measuring instrument



G. W. GROSS.

MEASURING INSTRUMENT.

APPLICATION FILED JULY 2?. 1918.

1,303,471. Patented May 13, 1919..

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GEORGE W. GROSS, OF SEATTLE, WASHINGTON.

MEASURING- INSTRUMENT.

Specification of Letters Patent.

Patented May 13, 1919.

Application filed July 27, 1918. Serial No. 247,334.

To all whom it may concern Be it known that 1, GEORGE W. Gross, citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented a certain new and useful Improvement in Measuring Instruments, of

which the following is a specification.

My invention relates to improvements in measuring instruments and more particularly to improvements in instruments of the general type including compasses, dividers, calipers and the like, and the object of my invention is to provide an instrument that is constructed with three or more legs instead of two so that the instrument may be set to take more than one measurement without making any adjustments.

A further object of my invention is to provide a simple and eflicient pivot joint for the legs of the instrument so that the legs may all be operatively disposed in the same plane and to provide a springy handle that is normally adapted to spread the legs of the instrument apart and suitable screw adjustment devices for retaining the legs of the instrument in any desired position against the pressure of the spring.

My invention consists in the novel construction, adaptation and combination of parts of a measuring instrument of the class described as will be more clearly hereinafter described and claimed.

In certain classes of work, particularly machine work it is often necessary to make two or more of the same measurements rcpeatedly and when this is done the workman usually employs more than one instrument so that he will not have to re-set the same for each measurement. The present invention obviates the necessity of using more than one instrument.

My invention is also useful where limit work is being done since one side may be set to the maximum distance and the other side to the minimum distance allowable for the work.

I accomplish these objects by devices illustrated in the accompanying drawings, where- 1n Figure 1 is a view in elevation of a pair of dividers or compasses constructed in accordance with my invention;

Fig. 2 is a view in sectional elevation substantially on broken line 2, 2 of Fig. 1;

Fig. 3 is a view partly in elevation and partly in cross-section illustrating a pivot ment; and

Fig. 4E shows a modified form of a point for the central leg of the instrument.

Referring to the drawings throughout which like reference numerals indicate like parts, the numerals 5 and 6 designate the two outer legs of a pair of dividers or compasses and 7 designates a medial leg that is disposed between the legs 5 and 6.

The two outer legs 5 and 6 and the medial leg 7 are pivotally connected at their upper ends by two floating rivets 8 that are adapted to fit within arcuate notches 10 in the inner edges of the outer legs 5 and 6 and other arcuate notches 11 in the opposite edges of the medial leg 7 as more clearly shown in Fig. 3, the heads of the rivets 8 being adapted to extend over the sides of the three legs 5, 6 and 7 to hold the three legs flush and in the same plane.

The top ends of the three legs 5, 6 and 7 are beveled as at 12 so that they will not strike against and interfere with each other as they are moved toward and away from each other and the outer edge of each of the outermost legs 5 and 6 is notched as at 13 above the line of the arcuate notches l0 and 11 for the reception of the ends of a flat arcuate steel spring 14 that exerts an inward pressure on both of the outer legs 5 and 6 above the centers of the rivets 8 and tends to spread the legs 5 and 6 apart.

The upper portion of the arcuate spring 14 isprovioled with a stem 15 that projects outwardly therefrom and serves as a finger hold by which the instrument may be manipulated. l i

The several legs 5, 6 and 7 are held in adj usted position with respect to each other by two threaded shanks 16 and.,l7 that are secured at their inner ends to studs 18 and 19 respectively that are pivotally secured to the medial leg 7 and project outwardly from opposite sides thereof and such two shanks 16 and 17 extend outwardly in substantially opposite directions through studs 20 and 21 respectively that are pivotally mounted on the outer legs 5 and 6 and project from opposite sides thereof.

The threaded shanks 16 and 17 are each provided 'with thumb screws 22 that are adapted to engage with the studs 20 and 21 to hold the several legs in adjusted position with respect to each other.

The medial'leg 7 is preferably provided with a removable point 23 that projects slightly beyond the points of the outer legs and 6 so that when the point of the medial leg and the point of one outer leg rest on a plane surface the point of the other outer leg will be withdrawn from or lifted above the plane of the other two points.

In Fig. 4 I have shown a modified form of, tip 24: for the medial leg 7 which tip is split as at 24 and recessed at its outer end in a well known manner for the reception of a point25 which may be of steel or may be of 'lead or graphite so that a pencil "mark may be made therewith, as, for instance two circles of different diameter may be described without re-setting the instrument. j

"Thepoint'25 is clamped within the end of the tip 24 by means of 'a screw 26 that screws'through lugs 27 so that the point 25 4 I may be adjusted lengthwise of the tip 24.

The device herein shown' may be set so that tli'ree difi'ereht measurements may be made therewith, one being madeby the use 'of the points of the legs 5 and 7 another being made by the use of'the points of the .legs 6 and 7 "and still another being made by use of the points of the legs 5 and 6.

It will be readily understood that this invention is as applicable to either inside oroutside calipers as it is to' dividers and compasses.

Obviously changes in the form of construction of the various parts of my inven- 'tion may be resorted to within the scope of the following claims What I claim is:

1. A measuring instrument of the class described, comprising a medial leg member, two outer leg members disposed on opposite sides of said medial leg member in the same plane therewith, pivot means connecting the upper ends of all of said leg members, an arcuate fiat spring engaging the two outer leg members above their pivotal point, and screw devices connecting each of said outer leg members with said medial leg member.

2. A measuring instrument of the class described comprising a medial leg member having an arcuate notch in each edge adjacent its upper end and having its upper end portion beveled, two outer leg members disposed on opposite sides of said medial leg member in the same plane therewith, said outer leg members each having an arcuate notch on the inner edge thereof adjacent the top end and being provided with other notches 'on their outer edges above said arcuate notches, the upper ends of said outer leg members being beveled to adapt them to clear said medial leg member, rivets having integral heads on both ends adapted to lap over the side surfaces of said leg members, the bodies of said rivets being adapted to fit within said arcuate notches, a flat arcuate spring having two ends that are "disposed within the notches 'on the outer edges of said two outer legs to spread said legsapart, and screw devices connecting each of said outer leg members with said medial leg member for adjusting the relative angular positions of said leg members.

3. A measuring instrument of the class described, comprising medial leg member, two outer leg members disposed on opposite sides of said medial leg member in the same plane therewith, pivots articulating the upper ends of all of said leg members,

an arcuate fiat spring engaging the two outer leg member's above the said pivots, studs projecting from opposite sides of said medial leg member and pivot'ally secured thereto, a threaded shank screwed to each of said studs, said slranks extending outwardly in substantially opposite directions, a pivotally mounted perforated stud "secured to each of said outer leg members, said shank being slidable through the perforations in said last na'mcd studs and thumb screws on said shank and adapted to engage said last named studs to hold said leg members in adjusted angular positions.

In witness whereof, I hereunto subscribe my name this 20th day of July, A. A. 1918.

GEORGE 'W. GROSS.

Copies of this patent may be obtained. for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

